Engine starter



July 13 1926. 1,591,987 W. L. M GRATH ENGINE STARTER Filed Jan. 7. 1921 2 Sheets-Sheet 1 July 13 1926. 1,591,987

w. L. M GRATH ENGINE STARTER Filed Jan. '7. 1921 2 sheets-Sheet 2 inc/672%? M72665 iivdd'w' Patented July 13, 1926.

UNITED STATES PATENT OFFICE.

WILLIAM L. MQGRATH, OF ELMIRA, NEW YORK, ASSIG-NOR TO ECLIPSE MACHINE COMPANY, OF ELMIRA. NEW YORK, A CORPORATION OF NEW YORK.

ENGINE STARTER.

Application filed January My invention relates to a starter for ail engine such as an internal combustion engine and the same pertains to the drive or transmission thereof which is Ior-ated between the prime mover such as an electric starting motor, and a member of the engine to be started, such as the flywheel thereof. The drive in which my invention is, in the present instance embodied, is of the screw shaft.

type on which a driving member such as a pinion is mounted for longitudinal movement to engage the engine member and for rotary movement therewith after such engagement. The object of my invention is to provide simple and eflicient means co= operating with the pinion so as to hold the same in its normal or home position on the shaft. A further object of my invention is to so construct and arrange said means as to provide for a support for the outer end of the pinion when in driving position and also while moving longitudinally to such position.

In the drawings Fig. 1 is an elevation, partly in section, of an enginestai'ter embodying my invention. Figs. 2, 3, 4 and 5, similar Views of modified forms of construction.

In the present instance I have shown my invention in connection with the Eclipse- Bendix type of drive and of the outboard variety but it willbe understood that my inventionis not to be limited thereto inasmuch as it may be applied to other types of drive and also to the inboard variety. Also while I have shown the drive as of the direct or single reduction type it will be understood that my invention is applicable to other types such as the double reduction. I

Referring to the construction as herein shown'in Fig. 1, the starting motor 1 is provided with an extended armature shaft 2 on which the drive or transmission is mounted and by which it is driven. A driving, head 3 is secured to the shaft 2 by the stud 1 and the same is operatively connected with the driven head 5 of the screw shaft by 'the drive spring 6 through the medium of the stud '7. The screw shaft has a screw threaded portion 8 at its inner end and a smooth portion 9 toward its outer end, such end terminating in a stop projection which is here in the form of a removable nut 10.

The driving member is here in the form of a pinion l1 threaded upon the screw 7, 1921. Serial No. 435,606.

threads 8 and having teeth 12 adapted to mesh with the teeth 13. of the engine memher which is here the flywheel 14 thereof. In the present instance the smooth portion 9 of the shaft is of the same diameter as the minimum diameter of the screw threaded .portion and the pinion is adapted to move sists of two parts, namely a coiled spring encircling said smooth portion 9 and a collar 17 located between the rearward end of such spring and the pinion. This collar which is adapted to slide upon said smooth portion 9 of the shaft is of the peculiar format-ion shown, the same being of two diameters, the larger one 18 which receives the inner end of the spring 16 and acts as a seat therefor and also as a partial pocket for the same. The lesser diameter 19 is of such diameter as to permit the counter-bore of the pinion to fit thereover and to act as a support for that end of the pinion while shifting longitudinally and also while in its driving position. This collar is limited in its movement to the right by suitable means which is here the shoulder 20 formed at the junction between the smooth and screw threaded portions of the screw shaft. By preference, a clearance is provided between the outer face of the pinion andthe collar 17 when the parts are in their normal position in order to provide for the proper acceleration of the motor before the pinion in its longitudinal movement contacts the collar.

The'stop nut 10 is made of the peculiar shape shown, in order to cooperate with the spring 16 and collar 17. To this end this nut is provided with a counter-bore 21 adapted to serve as a seat for the outer end of the spring and also to contain the outer coils thereof and to serve as a partial pocket for the same when compressed. The stop nut is also provided with an annular stop surface 22 against which the opposing surface 23 of the collar is adapted to contact when the parts are in driving position.

Describing a cycle of operation and beginning with the parts in their position shown, when the motor is operated the pinion will be automatically moved longitudinally to the left, and after a slight movement in that direction the pinion will contact the collar 17 and will move the same longitudinally to the left against the tension of the spring 16, This longitudinal movement will continue until the surfaces 22 and 23 are in engagement at which time the pinion which has partially telescoped the collar, is hearing against one of the right hand faces thereof. Also at this time the spring 16 is compressed and is contained within the pocket formed jointly by the counter-bores or annular recesses 18 and 21 so that such spring is relieved from any injurious compression.

The pinion in this longitudinal movement meshes with the flywheel and after this movement has been arrested the pinion will partake of the rotary movement of the screw shaft whereupon the flywheel will be rotated and the engine started. lVhen the engine starts on its own power the pinion will be demeshed in the usual manner and with the aid of the spring 16 which has the additional function of preventing any creeping or drifting of the pinion against the flywheel.

In Fig. 2 I have shown a modified form of construction in which the parts are the same with the exception of the stop nut which is here a plain nut 24, and with the exception of the collar 25 which is here provided with an annular recess 26 of greater length than the recess 18 so as to form the complete pocket for the spring 27. In other respects the construction is the same and similar reference numerals are applied.

In Fig. 3 I have shown another modified form of construction in which the stop nut 10 is the same as before but the collar 17 is omitted and the inner coil of the spring 16 is adapted to enter the counter-bore or annular recess 15 ofthe pinion. In this construction the recess 15 of the pinion and the recess 18 of the nut form the complete pocket for the spring 16.

In Fig. 4 I have shown a spring similar to Fig. 3 with the exception that the recess 15 of the pinion is deepened and a small ring or collar 28 is interposed between the spring 16 and the bottom of the recess 15.

In' the constructions illustrated in Figs. 1 to 4, the screw shaft is provided with a smooth portion 9 but in Fig. 5 I have shown a shaft having screw threads throughout, that is, with no plain portion, so that the pinion is screw threaded upon the shaft as far as the stop nut 10. According to this construction the spring 16 and its associated elements are the same as in Fig. 3 with the exception that such spring is of slightly greater diameter and consequently the recesses l5 and 18 are of correspondingly greater diameter.

I claim:

1. An engine starter drive including a driving shaft having a stop projection thereon which is annularly recessed immediately adjacent the shaft, a driving member mounted on the shaft for longitudinal movement thereon to engage a member of the engine to be started, and to contact said projection at a point beyond such annular recess and for rotary movement with such shaft, and a coiled spring encircling the shaft and interposed between the driving member and the stop projection with the coils at one end received by the said annular recess,said spring extending across the plane of the engine member.

2. An engine starter drive including a driving shaft having a stop projection thereon which is annularly recessed, a driving member mounted on the shaft for longitudinal movement thereon to engage a member of the engine to be started, and to contact said projection and for rotary movement with such shaft, and a coiled spring en-.

circling the shaft and interposed between the driving member and the stop projection with the coils at one end received by the said annular recess and with the body of the spring extending in advance "of such recess, and a member having a similar annular recess to receive the spring coils at the other end of the spring, said spring extending across the plane of the engine member.

3. An engine starter drive including a driving shaft having a stop nut thereon provided on one side with an annular recess immediately adjacent the shaft and with a contact surface therebeyond, a pinion mounted on the shaft for longitudinal movement thereon to engage a member of the engine to be started and for rotary movement with such shaft, a light coiled spring encircling the shaft and interposed between the stop nut and the pinion and extending across the plane of the engine member, and means located at the engaging end of the pinion to receive one end of the spring, the end coils of the spring being received by said recess and said means and contained therewithin when the said means is in contact with said contact surface of the nut and the spring is thereupon compressed.

t. An en 'ne starter drive including a driving shat having a stop, a driving member mounted on the shaft for rotary movement therewith and for longitudinal movement thereof into engagement with a member of the engine to be started, a collar loosely mounted on the shaft between the stop and the driving member and movable across the vplane of the engine member, and

- a coiled spring interposed between the stop ber mounted onthe shaft for rotary movement therewith and longitudinal movement thereof into engagement with a member of the engine to be started, a collar loosely V mounted on the'shaft between the stop and the driving member and movable across the plane of the engine member, and a coiled spring interposed between the stop and the collar, said collar having an annular recess forming a seat and pocket for the coils of the spring. a

n 6. An engine starter drive including a driving shaft having a stop, a driving member mounted on the shaft for rotary move 'ment therewith and longitudinal movement thereof intoengagement with a member of the engine to be started, a collar loosely mounted on the shaft between the stop and the driving member and movable across the plane of the engine member, a coiled spring interposed between the stop and the collar,

and means for stopping the movement of the collar towards the driving member.

7. An engine starter drive including a driving shaft having a stop, a driving member mounted on the shaft for rotary movement therewith and longitudinal movement thereof into engagement with a member of the engine to be started, a collar loosely mounted on the shaft between the stop and the driving member and movable across the plane of the en ine member, and a coiled spring interpose between the stop and the collar, said collar and stop having annular recesses to receive and contain the spring coils when compressed.

8. An engine starter drive including a driving shaft having a screw threaded portion and also a smooth portion at one end, a stop at said end, a driving member threaded onthe shaft for longitudinal movement thereof and over said smooth portion and for rotary movement with the shaft, a collar loosely mounted onthe smooth portion, and a spring encircling said smooth portion and interposed between the stop and the collar, said drivin member and collar telescoping for supporting the former during its longitudinal movement over said smooth portion of the shaft.

9. An engine starter drive including a driving shaft having a screw threaded portion and also a smooth portion at one end, a stop at said end, a driving member threaded on the shaft for longitudinal movement thereof and over said smooth portion and for rotary movement with the shaft, a collar loosely mounted on said smooth portion, and a spring encircling said smooth portion and interposed between the sto and the collar, said stop and collar. having annular recesses to receive the spring coils when compressed and said driving member and collar telescoping with each other for a stop at said end,-'a driving member threaded on the shaft'for' longitudinalmovement thereof to engage a member of the engine to be started, such movement being along said smooth portion and against the stop, and for rotary movement with such shaft, a collar loosely mounted on said smooth portion of the shaft, and a light spring encircling said smooth portion and interposed between the stop and the collar without interfering with the functioning of the driving member but in position to exert pressure on the driving member prior to its engagement with the engine member, and means located adjacent the driving member when in normal position on the shaft for stopping the movement of the collar towards the driving member in such position as to be contacted -by the driving member in its longitudinal movement before engaging the engine member.

11. An engine starter drive including a driving shaft having a screw threaded portion and also a smooth portion at one end,

and for rotary movement with such shaft,

a collar loosely mounted on said smooth portion of the shaft, and a light spring encircling said smooth portion and interposed between the stop and the collar without interfering with the functioning of the driv ing member but in position to exert pres Sure on the driving member prior to its engagement with the engine member, said shaft being formed with a stop means for stopping the movement of the collar towards the driving member in such position as to be contacted by the driving member in its longitudinal movement before engaging the engine member.

12. An engine starter drive including a driving shaft having a screw threaded portion and also a smooth portion at one end, a stop at said end, a driving member threaded on the shaft for longitudinal movement thereof against the stop and for rotary movement with the shaft, a collar loosely mounted on the smooth portion and having a peripheral portion adapted to contact the stop, and a spring encircling said smooth portion and interposed between the stop and the collar, said stop and collar having similar annular recesses of a size to receive the spring coils and to contain them when compressed, said collar and driving member having a partial telescoping fit.

13. An engine starter drive including a driving shaft having a screw threaded portion and also a smooth portion at one end,

a stop at said end, a driving member threaded on the shaft for rotary movement therewith and for longitudinal movement thereof into engagement with a member of the engine to be started, a collar loosely mounted on the smooth portion and having a peripheral portion adapted to contact the stop, and a spring encircling said smooth portion and interposed between the stop and the collar in position to exert its pressure on the latter prior to engagement of the driving member with the engine member, said smooth portion being of lesser diameter than the screw threaded portion whereby a stop shoulder is formed at the junction of said two portions to arrest the longitudinal movement of the collar towards the engine member, and such smooth portion extending across the plane of the engine member whereby said collar is adjacent the driving member when in normal position and is moved by such driving member across such plane.

14. An engine starter drive including a driving shaft having a screw threaded portion and also a smooth portion at one end, a stop at said end, a driving member threaded on the shaft for longitudinal movement thereof against the stop .and for rotary movement with the shaft, a collar loosely mounted on the smooth portion, and a spring encircling said smooth portion and interposed between the stop and the collar, said driving member having a counterbore to fit upon the collar.

15. An engine starter drive including a driving shaft having a screw threaded portion and also a smooth portion at one end, a stop at said end, a driving member threaded on the shaft for longitudinal movement thereof against the sto and for rotary movement with the sha t, a collar loosely mounted on the smooth portion, and a spring encircling said smooth portion and interposed between the stop and the collar, said driving member having a counterbore adjacent the collar, said collar being of two diameters, the larger of which receives one end of the spring and the lesser of which is received by said counterbore.

. WILLIAM L. MCGRATH. 

